• 제어로봇시스템학회논문지
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• 제8권10호
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• pp.881-889
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• 2002

Mobility analysis for various mobile mechanisms including mechanisms with lack of geometric generality is performed. Joint screws are employed to find the sire of feasible joint motion space or each of independent loops of mobile mechanisms. Particularly, the concept of "representative screws" is introduced to represent the feasible motion spaces for subsets of joints belonging to either a loop or a sub-system consisting of several closed loops. Firstly. simplified joint model for each of low different typical wheels popularly employed in mobile robots is described. Then. mobility analysis fir various types of planar mobile robots and the Mars Rover mobile robot for navigation on the rocky road on Mars arc performed. It is confirmed that the obtained results in this study coincide with the previous ones which were obtained by suing imaginary Joints approach(1)pproach(1)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.6.1-6.9
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• 2015

Orthognathic surgery requires stable fixation for uneventful healing of osteotomized bony segments and optimal remodeling. Titanium plates and screws have been accepted as the gold standard for rigid fixation in orthognathic surgery. Although titanium osteofixation is the most widely used approach, the use of bioabsorbable devices has been increasing recently. Biodegradation of bioabsorbable devices eliminates the need for a second operation to remove metal plates and screws. However, long-term stability and relapse frequency in bioabsorbable osteofixation are still insufficiently studied, especially in cases of segmental movements of great magnitude or segmental movements to a position where bony resistance exists. This paper reviews the background, techniques, and complications of bioabsorbable osteofixation and compares bioabsorbable and titanium osteofixation in orthognathic surgery in terms of skeletal stability.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.943-953
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• 1999

Severe alveolar ridge deficiency can prevent ideal implant placement. Ridge augmentation procedures are necessary to regain lost alveolar structures. The corticocancellous block bone graft was harvested from the mandibular symphysis. This block bone was fixed to the lateral aspect of the ridge with titanium screws. Seven months later, the autogenous bone graft was reentered and sufficient bone volume was gained to allow implant placement. The fixation screws were removed and 3I implants were inserted. No complication and postoperative alteration in chin contour were observed. This report demonstrates that chin graft offers a predictable alternative in the reconstruction of ridge deficiency for implant placement.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.167-168
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• 1998

The purpose of this study is to verify the biomechanical characteristics of the custom-made(our) pedicle screws which are designed the different types of shape, pitch, and profile. The results of experiments for our pedicle screw were summarized. 1) The screw of larger outer diameter showed greater holding strength. 2) The holding strength of cylindrical shaped screw was superior to that of conical shaped screw. 3) The holding strength of buttress shape of thread profile showed superior to that of V-shape. 4) The pull out and holding strength of our pedicle screws was superior to that of commercialized screw (Diapason and CD) which is widely used.

• 한국임상수의학회지
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• 제20권1호
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• pp.138-141
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• 2003

First case, a one-year-old female Shih Tzu weighing 3 kg with closed transverse fractures of bilateral mandibular body between 2nd and 3rd premolar teeth were treated surgically with bone plates and screws, and cranial luxation of temporomandibular joints were reduced to closed method. Second case, a 8.4 years old male Yorkshire terrier weighing 2.6 kg with closed transverse/oblique fractures of bilateral mandibular body between premolar and molar teeth were treated surgically with bone plates and screws. Radiographic examination revealed that the fractures in two cases fixed well and temporomandibular joint was stabilized. One month after operation, jaw activity was excellent and malocclusion wasn't observed.

• Journal of Chest Surgery
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• 제32권9호
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• pp.844-846
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• 1999

이물질(foreign body)의 만성적인 자극은 혈관에 지연성 손상을 가져올 수 있다. 척추 측후만증을 교정하고 자 약 14개월 전에 흉추에 CD 금속강과 나사못(Cotrel-Dubousset rods and screws)을 장치했던 환자에서 CD 나사못의 만성적인 자극으로 흉벽의 박동성 혈종을 합병한 가성 대동맥류가 발생하였다. 이 환자에서 가성 대동맥류가 발생한 하행대동맥 부위를 절제하고 인조혈관 대치술로 치료하였기에 보고한다.

• Clinics in Shoulder and Elbow
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• 제22권3호
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• pp.149-153
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• 2019

We experienced acromial erosion and subsequent fracture after the treatment of Rockwood type V acromioclavicular dislocation with hook plate and coracoclavicular ligament augmentation. It was treated by using a surgical technique to address an acromial fracture and subsequent losses of reduction in acromioclavicular joint with two trans-acromial cortical screws (crossbar technique). The reduction state of acromioclavicular joint could be maintained by these two screws. Our crossbar technique could be considered as a good salvage procedure for the reduction loss caused by cutout or significant erosion of acromion after insertion of clavicular hook plate.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2007년도 제15차 대한견주관절학회 및 제3차 Mayo Asia Elbow Club 합동 학술대회
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• pp.85-85
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• 2007

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 2001년도 추계학술대회
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• pp.44-44
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• 2001

• Journal of Korean Neurosurgical Society
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• 제57권4호
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• pp.229-234
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• 2015

Objective : Pedicle screw fixation for spine arthrodesis is a useful procedure for the treatment of spinal disorders. However, instrument failure often occurs, and pedicle screw loosening is the initial step of a range of complications. The authors recently used a modified transpedicular polymethylmethacrylate (PMMA) screw augmentation technique to overcome pedicle screw loosening. Here, they report on the laboratory testing of pedicle screws inserted using this modified technique. Methods : To evaluate pullout strengths three cadaveric spinal columns were used. Three pedicle screw insertion methods were utilized to compare pullout strength; the three methods used were; control (C), traditional transpedicular PMMA augmentation technique (T), and the modified transpedicular augmentation technique (M). After control screws had been pulled out, loosening with instrument was made. Screw augmentations were executed and screw pullout strength was rechecked. Results : Pedicle screws augmented using the modified technique for pedicle screw loosening had higher pullout strengths than the control ($1106.2{\pm}458.0N$ vs. $741.2{\pm}269.5N$; p=0.001). Traditional transpedicular augmentation achieved a mean pullout strength similar to that of the control group ($657.5{\pm}172.3N$ vs. $724.5{\pm}234.4N$; p=0.537). The modified technique had higher strength than the traditional PMMA augmentation technique ($1070.8{\pm}358.6N$ vs. $652.2{\pm}185.5N$; p=0.023). Conclusion : The modified PMMA transpedicular screw augmentation technique is a straightforward, effective surgical procedure for treating pedicle screw loosening, and exhibits greater pullout strength than traditional PMMA transpedicular augmentation. However, long-term clinical evaluation is required.